WATER PROTON NUCLEAR MAGNETIC-RELAXATION IN HETEROGENEOUS SYSTEMS - HYDRATED LYSOZYME RESULTS
WATER PROTON NUCLEAR MAGNETIC-RELAXATION IN HETEROGENEOUS SYSTEMS - HYDRATED LYSOZYME RESULTS
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DOI：
10.1002/mrm.1910220115
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发表时间：
1991-11-01
影响因子：
3.3
通讯作者：
BRYANT, RG
中科院分区：
文献类型：
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作者：
LESTER, CC;BRYANT, RG
测量水合固定化溶菌酶中水质子的自旋晶格弛豫速率作为磁场强度的函数。水弛豫对水合的依赖性呈现为35至55%重量含水量。水-质子弛豫与蛋白质的弛豫直接耦合，并且这种耦合在没有化学交换的情况下存在。应用模型，其中两个质子相中的弛豫通过偶极交叉弛豫机制以及化学交换耦合。观察到的水-质子弛豫曲线的幅度与蛋白质与水质子的比率以及蛋白质-质子弛豫速率成比例。蛋白质-质子自旋-晶格弛豫的场依赖性在D2 O存在下呈现，其中不存在交叉弛豫耦合。耦合弛豫模型很好地解释了作为磁场强度的函数的NMR弛豫数据，这类似于对诸如组织的其他异质系统的测量。出版社：Academic Press，Inc.
Spin‐lattice relaxation rates of water protons in hydrated immobilized lysozyme are measured as a function of magnetic field strength. The dependence of water relaxation versus hydration is presented from 35 to 55% by weight water content. The water‐proton relaxation is directly coupled to that of the protein and the coupling exists in the absence of chemical exchange. A model is applied where relaxation within the two proton phases is coupled through a dipolar cross‐relaxation mechanism as well as chemical exchange. The observed amplitudes of the water‐proton relaxation profiles scale with the ratio of protein to water protons as well as the protein‐proton relaxation rate. The field dependence of the protein‐proton spin‐lattice relaxation is presented in the presence of D2O where a cross‐relaxation coupling is absent. The coupled relaxation model accounts well for the NMR relaxation data as a function of magnetic field strength which is similar to measurements on other heterogeneous systems such as tissues. © 1991 Academic Press, Inc.